If Iranian government operatives really did try to contract a Mexican drug cartel to assassinate the Saudi ambassador to the U.S., as the Obama Administration alleges today, then they weren’t just being diabolical. They were being fairly stupid.

Granted, the Zetas – the drug mafia that Iranian-American Manssor Arbabsiar allegedly thought he was dealing with on behalf of Tehran – are certainly Mexico’s most bloodthirsty: they are the narcos that brought beheadings and wholesale massacres of innocent civilians to the nightmarish drug war scene south of the border. But even the Zetas, founded more than a decade ago by former Mexican army commandos, know better than to venture north of the border and invite the kind of U.S. law enforcement heat that a political assassination of this magnitude would have brought on them. …

It also seems an organization like the Iranian Revolutionary Guard, for whom the Justice Department says Arbabsiar may have been working, should know better. Arbabsiar, who lives near Mexico in Corpus Christi, Texas, certainly should have been wiser.

Or perhaps Tehran has been listening to all the right-wing hysteria about Mexican drug violence spilling across the border into the U.S. The problem: for the reasons I cite above, it’s simply not true.

The U.S. side of the border, in fact, is one of the safest corridors in America. According to the F.B.I., the four large U.S. cities with the lowest violent crime rates are all in border states. That’s not exactly an indication that Mexican drug gangs like the Zetas are eager to rain down bombs and bullets further north in cities like Washington, D.C., where the Saudi ambassador assassination was supposedly to have taken place.